Mitigating irreversible capacity loss for higher-energy lithium batteries

Abstract

After 30 years’ optimization, the energy density of Li ion batteries (LIBs) is approaching to 300 Wh kg−1 at the cell level. However, as the high-energy Ni-rich NCM cathodes mature and commercialize at a large-scale, the energy increase margin for LIBs is becoming limited. To further hoist the energy density of LIBs, strategies to mitigate capacity loss (MCL) were proposed and have been flourishing in recent years, which not only can effectively compensate the Li+ consumption for the formation of solid electrolyte interface (SEI) in the initial charge process, but also efficiently offset the Li+ loss in subsequent cycling. In this review, various MCL strategies are comprehensively summarized with particular focus on the chemistry and interfacial reaction mechanisms, while the merits and shortcomings of each method (artificial SEI, pre-lithiation, sacrificial additives, etc.) are analyzed and compared in view of their prospective applications in LIBs and beyond. Additionally, the MCL methods in Li-S, Li-O2 and Li-ion capacitors are also discussed due to their comparable energy-storage mechanisms, which could act as a reference for the advancement of MCL in new high-energy battery chemistries. Finally, the perspectives towards promising directions on various MCL strategies are provided to help realize practical higher energy LIBs.